1. Field of the Invention
The present invention relates to a label for use in in-mold molding in which the label is set in a mold so that the printed side of the label comes into contact with the mold wall and molding is then conducted by introducing a parison of a molten thermoplastic resin into the mold to conduct blow molding or by injection-molding a molted thermoplastic resin in the mold or by introducing a sheet of a molten thermoplastic resin into the mold to conduct vacuum forming or pressure forming to thereby produce a labeled molded article. The invention further relates to a molded article obtained using the label.
2. Description of the Related Art
In processes heretofore in use for integrally molding a labeled molded resin container, a blank or label is inserted beforehand into a mold and a container is then molded in the mold by injection molding, blow molding, differential pressure molding, foam molding, or the like to decorate or otherwise label the container (see, for example, patent document 1: JP-A-58-069015 and patent document 2: JP-A-01-125225). Proposed as such in-mold labels are, for example, a label obtained by subjecting crystalline polypropylene, polyethylene, etc. to extrusion molding or calendaring to obtain a transparent film for use as a base, applying a solution of a low-melting olefin resin such as an ethylene/vinyl acetate copolymer to the base with a gravure coater or the like, and drying the coating and a label obtained by laminating a low-melting olefin resin film to that base with an adhesive or by directly laminating the film to the base by extrusion laminating.
However, use of the transparent film thus obtained has had the following drawback. In the case where the labels are subjected to sheet-by-sheet offset printing, when a trouble such as the so-called scumming, which is the phenomenon in which ink transfer to non-image areas occurs due to a deficiency of dampening water, arises during the printing, it is difficult to notice the trouble through an inspection in which one sheet being printed is drawn out. The occurrence of scumming is noticed only when the stack of prints amounts to about several thousand sheets, and re-printing is then conducted, resulting in a printing loss. Namely, there has been a problem that it is difficult to regulate ink transfer during continuous printing (see, for example, patent document 3: JP-A-2002-240131 and patent document 4: JP-A-2002-321274).
A method has hence been employed in which several white printing papers are inserted at intervals of several hundreds of sheets and printed to examine the degree of scumming and conduct dampening water regulation based on the examination. After the printing, the white printing papers should be taken out and examined for any printing trouble, before the printed matters obtained from the transparent film are shipped. There has hence been a problem that the printing step takes many days and is costly.